WCAG 2.1 Level AAA is the highest accessibility level, requiring a contrast ratio of at least 7:1 for normal text and 4.5:1 for large text.

Do I need to meet AAA?

AAA is not required by most regulations, but it is best practice for body text and high-readability contexts. AA is the minimum legal requirement in many jurisdictions.

Is it possible to meet both AA and AAA?

Yes. Any combination that passes AAA (≥7:1 for normal text) automatically passes AA (≥4.5:1). Pure black on white is 21:1, the maximum possible ratio.

WCAG AAA contrast checker

Check whether your colour pair meets WCAG 2.1 Level AAA, the enhanced accessibility standard with stricter contrast requirements. Meeting AAA is recommended for body text and critical UI elements.

Foreground (text)

Background

Aa Large text sampleNormal body text sample, the quick brown fox jumps over the lazy dog.

Contrast ratio	21.00 : 1
AAA. Normal text (≥7:1)	pass
AAA. Large text (≥4.5:1)	pass

MODE

PRESETS

Runs entirely in your browser

How it works

WCAG contrast is computed using relative luminance: each sRGB channel is linearised (gamma-corrected), then combined as L = 0.2126R + 0.7152G + 0.0722B. The ratio is (L1 + 0.05) / (L2 + 0.05) where L1 is the lighter colour. APCA uses the separate APCA-W3 0.0.98G algorithm which accounts for polarity and produces an Lc value. All computation runs entirely in your browser.

Processing runs in your browser

All contrast calculations happen in your browser tab. Our servers are not involved at any point.

Related operations

To swap a HEX value into RGB or HSL while testing, try the colour converter. For generating an accessible swatch set from a brand colour, use the colour palette generator. To create lighter or darker variants that still pass contrast, see tints and shades.

Frequently asked questions

What is WCAG AAA?: WCAG 2.1 Level AAA is the highest accessibility level, requiring a contrast ratio of at least 7:1 for normal text and 4.5:1 for large text.
Do I need to meet AAA?: AAA is not required by most regulations, but it is best practice for body text and high-readability contexts. AA is the minimum legal requirement in many jurisdictions.
Is it possible to meet both AA and AAA?: Yes. Any combination that passes AAA (≥7:1 for normal text) automatically passes AA (≥4.5:1). Pure black on white is 21:1, the maximum possible ratio.

WCAG AAA contrast checker

How it works

Processing runs in your browser

Related operations

Frequently asked questions

Related tools